1. Field of Invention
The present invention relates to nuclear techniques for detecting water cut and water salinity in an oil/water flowstream in petroleum refining and producing operations.
2. Description of the Prior Art
U.S. patent application Ser. No. 748,072 relates to a new and improved method and apparatus for determining the presence of salt water in a fluid conduit, such as crude oil at a wellhead, loading dock or other location, or refined product, feed stock or waste water to dispose of at a refinery.
With this technique, the fluid is bombarded with fast neutrons from a neutron source which are slowed down and thereafter engage in thermal neutron capture reactions with materials in the fluid, giving rise to thermal neutron capture gamma rays. The energy spectra of the thermal neutron capture gamma rays are obtained, from which a measure of the relative presence of chlorine in the fluid may be ascertained, so that if the salinity of the fluid is known, the relative presence of salt water can accordingly be determined. Further, the relative presence of sulfur may under certain conditions be determined simultaneously with the relative presence of chlorine.
In many petroleum field applications, however, the produced fluid water salinity may vary. This is frequently the case in fields where water flooding (or steam flooding) with other than connate water is utilized. In these situations, the water cut of the salt water cannot be established unless corrections were made for salinity variations, which are difficult to quickly and accurately observe and determine.